A couple white spots on rocks and snails

[NEPAReefer]

Just wondering if someone can help identify the white spots in the picture. It is only on one rock and one snail right now. But I would like to tackle it before it gets out of hand if it is a problem.
Thanks everyone

 

[Girthrockwel]

I wonder if they're some sort of egg?

 

[cloak]

Yeah, they look like Nerite snail eggs IMO.